<b_jonas> slashlearn euclid//Euclid is a short geeky game in which the goal is to do Euclidean compass and straightedge constructions in as few steps as possible. It runs in the browser, found at "http://www.euclidthegame.com/". It was popular among #esoteric regulars in 2016-07.

#!/usr/bin/perl
sub k{my$t;$t=~y/IVXLC/XLCDM/,$t.=("",I,II,III,IV,V,VI,VII,VIII,IX)[$_]for/./g;$r{$t}=$_;$t}k for s""\$"..4e3;print $r{(shift=~/(\w+)/)[0]},$/